Spanish toothcarp (Aphanius iberus)

GenusAphanius (1)
SizeMale total length: 4.5 cm (2)
Female total length: 6 cm (2)

Classified as Endangered (EN) on the IUCN Red List (1).

Commonly known in its native Spain as the ‘fartet’, the Spanish toothcarp is a small fish in which the appearance of the male and female is dramatically different (2). The male is the smaller sex and has a colouration pattern consisting of narrow, silver, vertical bars running along the body and tail (2). The larger female’s body is covered in numerous small, dark spots that form horizontal rows, one of which runs along the lateral line (a line of pressure sensors that runs down the side of the body in fish) (2).

The Spanish toothcarp occurs along the Mediterranean coast of Spain (1), and possibly also in north-western Algeria, although it is thought that this population may be a separate species that has not yet been classified (1).

Historically, the Spanish toothcarp, which is able to adapt to a large range of temperatures and salinities (2), inhabited a large range of lowland waters. Today, however, its distribution is limited to salt marshes and coastal lagoons (3).

The Spanish toothcarp is an omnivorous fish that feeds on plant matter, copepods (small aquatic crustaceans), mosquito larvae and debris; however, its diet can vary greatly depending on which habitat it occupies (3).

The Spanish toothcarp’s reproductive strategy is adapted to living in an unstable environment, as it reaches sexual maturity after just a few months and shows a high reproductive effort (2), producing multiple batches of 10 to 30 eggs between May and August (4). The life history of the Spanish toothcarp is characterised by fast growth and a short lifespan, with most adults not living longer than around two years (2). It grows seasonally, with the growth period lasting from March to September, and the larger females have both a higher growth rate and tend to live longer than males (4). 

Populations of the Spanish toothcarp are estimated to have declined by at least 50 percent in the past ten years and, with numbers continuing to decrease, its threatened status shows no signs of improving (1). This population decline is due in part to competition with the mosquitofish (Gambusia holbrooki) (2); introduced by man to the region as a method of  controlling mosquito numbers, this fish is one of the most invasive fish species worldwide (5). As a result, the Spanish toothcarp is now restricted to bodies of water where the mosquitofish is absent (1).

Habitat loss is the other major threat facing the Spanish toothcarp, as tourism and intensive agriculture over the last 30 years has led to the destruction and alteration of the toothcarp’s habitat (2). Pollutants, such as nitrate fertilisers that have been washed into streams and lakes from local golf courses, are also degrading this species’ habitat (2).

The Spanish toothcarp has been the focus of a number of conservation actions.  A project in Catalonia, running from 1996 until 2000, worked to conserve the toothcarp and other species, and a captive breeding program resulted in 20,000 Spanish toothcarps being released back into the wild (6). In Murcia, conservation efforts have included the elimination of the invasive fish species, habitat management and restoration, and captive breeding of the Spanish toothcarp (7). However, whilst introductions of captive bred individuals help boost population numbers of this species, the threats to the Spanish toothcarp’s natural habitat need to be tackled if its future is to be secured (1).

To find out about other conservation efforts in Spain visit:

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  1. IUCN Red List (March, 2010)
  2. Oliva-Paterna, F J., Torralva, M. and Fernàndez-Delgado, C. (2006) Threatened fishes of the world Aphanius iberus. Environmental Biology of Fishes, 75:307-309.
  3. Alcaraz, C. and García-Berthou, E. (2007) Food of an endangered cyprinodont (Aphanius iberus): ontogenetic diet shift and prey electivity. Environmental Biology of Fishes, 78: 193-207.
  4. Vargas, M.J. and  De Sostoa, A. (1997) Life-history pattern of the Iberian toothcarp Aphanius iberus (Pisces, Cyprinodontidae) from a Mediterranean estuary, the Ebro delta (Spain). Netherlands Journal of Zoology, 47(2): 143-160.
  5. Alcaraz, C. and García-Berthou, E. (2007) Life history variation of invasive mosquitofish (Gambusia holbrooki) along a salinity gradient. Biological Conservation, 139: 83-92.
  6. Conservation of priority species in Mediterranean marshes (March, 2010)
  7. Conservation of Aphanius iberus genetic stocks (March, 2010)